From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Kleikamp Subject: Re: [RFC] [PATCH] Generic mpage_writepage() support Date: Wed, 16 Feb 2005 13:43:54 -0600 Message-ID: <1108583034.8157.23.camel@localhost> References: <1108409415.20053.1278.camel@dyn318077bld.beaverton.ibm.com> <20050214134058.1402cfed.akpm@osdl.org> <1108430825.20053.1363.camel@dyn318077bld.beaverton.ibm.com> <20050214190556.07c4a0c9.akpm@osdl.org> <1108485967.20053.1438.camel@dyn318077bld.beaverton.ibm.com> <20050215095443.3e646401.akpm@osdl.org> <1108512141.20053.1490.camel@dyn318077bld.beaverton.ibm.com> <16915.12661.494053.290059@gargle.gargle.HOWL> <1108579020.20053.1513.camel@dyn318077bld.beaverton.ibm.com> <1108580964.8121.12.camel@localhost> <1108582105.20053.1517.camel@dyn318077bld.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Nikita Danilov , fsdevel , ext2-devel To: Badari Pulavarty In-Reply-To: <1108582105.20053.1517.camel@dyn318077bld.beaverton.ibm.com> Sender: ext2-devel-admin@lists.sourceforge.net Errors-To: ext2-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: List-Id: linux-fsdevel.vger.kernel.org On Wed, 2005-02-16 at 11:28 -0800, Badari Pulavarty wrote: > On Wed, 2005-02-16 at 11:09, Dave Kleikamp wrote: > > On Wed, 2005-02-16 at 10:37 -0800, Badari Pulavarty wrote: > > > > > Yes. page->private is assumed for the bufferhead usage. Do you really > > > need for handling page->private for non-bufferhead usage ? > > > > For what it's worth, I'm working on some changes to jfs that will use > > page->private for non-bufferhead usage for metadata, but I won't be > > using a generic writepage, so it's not an issue for me. > > Nope. it would be an issue for you, since jfs uses mpage_writepages() > which uses the same code - which thinks page->private as bufferhead. The patch I am working on will call mpage_writepages() for metadata, but will use my own writepage() rather than mpage_writepage(), and nothing in mpage_writepages() will use page->private. For normal data, page->private, if used at all, will be bufferheads. > > > > mpage.c already assumes page->private implies bufferheads, so it's not > > completely generic. Would implementing this as nobh_write_full_page, to > > complement block_write_full_page, make sense? > > I guess, it can be done. So to really deal with this, we need to come > up with generic writepage/writepages interfaces which doesn't deal > with bufferheads. I'm not sure how useful that would be. Are there any users of a non-bufferhead page->private that want to call a generic writepage(s)? In other words, if a generic function is sufficient, you probably wouldn't be using page->private anyway. -- David Kleikamp IBM Linux Technology Center ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click